Mechanism fob rotating earth-drill bits



W. NIPPERT.

MECHANISM FOR ROTATING EARTH'DRILL BITS. APPLICATION FILED MAY 23.19l9.

1,318,225 Patented Oct. 7, 1919.

WITNESSES W l/WE/VZ'OR @FFTQE WORLEY NIPPERT, OF VERNON, TEXAS.

MECHANISM FOR ROTATING EARTH-DRILL BITS.

Specification of Letters Patent.

Patented Oct. 7, 1919.

Application filed may 23, 1919. Serial No. 299,247.

To all whom it may concern:

Be it known that I, VVORLEY NIPPER'r, a citizen of the United States, and a resident of Vernon, in the county of Wilbarger and State of Texas, have invented certain. new and useful Improvements in Mechanism for Rotating Earth-Drill Bits, of which the following is a specification. v

This invention relates to earth drills and has reference more particularly to mechanism for rotating such drills in a cable rig in which a jig or up and down motion is given to the same.

An object of the invention is to provide a drilling mechanism in which the drilling operation will be erformed solely by the weight of the drill stem.

Another object is to provide a drilling mechanism which shall by rapid reciprocalrotation o'f the drill cause around hole to be made, and to prevent packing up the walls of the well to prevent communication therewith of various strata.

The invention consists further in certain novel features of construction, arrangement and combination of parts for carrying the above function into effect, as will be hereinafter fully described and pointed out in. the claims, reference being had to the accompanying drawing, in which Figure 1 is a vertical longitudinal section of the mechanism;

Fig. 2 is a detail sectional view taken at the point indicated by line 22 of Fig. 1.

WVhen digging with the ordinary cable rig, it is necessary to turn the bit back and forth in order to dig a round hole, and. if this is not done a fiat hole results. Flat holes cause considerable trouble, and the expense of under-reaming when in hard formations.

The present invention is intended to prevent forming flat holes, and insure a round hole in all cases, the bit being turned or a] ternately rotated back and forth at each stroke of the drill stem.

When digging with the common rotary rig, in which the drill is continuously to tated in the same direction, the walls of the well become packed in tight by such continuous rotary mot-ion and frequently a Stratum of water or gas is cut off from the well by such packed walls.

To overcome all these defects and objections, I have devised the device illustrated and which consists of a heavy tubular steel socket or housing 1, the upper end of which is internally threaded, in which is screwed a steel plug 2 threaded at both ends and having an intermediate stop collar 2 within the bore of the socket, the walls are provided with a spiral groove 3, having a semicircular cross section and extending from near the lower end of the socket upwardly any suitable distance. A heavy steel rod or shank 4, having a circular cross section, is inserted in the lower end of the'socket, and this rod has in its outer face a spiral groove 5, semi-circular in cross section and of the same pitch as the spiral groove 3, in the bore of the socket. The spiral grooves 3 and 5 form complementary ball races for the ball 6, which constitutes the coupling means between the socket and the shank 4; at-the lower end of rod l. A rigid collar or shoulder 7 is provided and to this the bit 8 is attached, preferably by threaded couplings.

Before the plug 2 is screwed into the upper end of the socket an expansion coil spring'9 is placed within the bore its lower end bearing on top of the rod 4, the plug 2 is then screwed into place, and to its upper threaded end the lower end of the drill stem 10 is screwed, the lower end of the stem abutting the collar 2 which abuts the upper end of the socket, making a strong and smooth coupling.

For the purpose of keeping the ball race free of sand and gravel, I provide a flat spring finger 11, having a rounded point 12,

and mount it in the wall of the socket adjacent its lower end, as indicated by the section line 22 in Fig. 1. The finger projects into the ball race as the socket or housing moves up and down on the rod e.

The mechanism as hereinbefore set forth having been attached to the drill'stem which is carried at the lower end of the cable of the ordinary cable rig, the operation is as follows:

The weight of the drill stem being placed on the mechanism, the socket or housing moves downwardly with the drill stem; this downward movement acting on the ball in the cooperating grooves 8 and 5 causes the rod or shank 4: to rotate and when the drill stem 10 is raised the coil spring 9 forces the shank 4: out of the socket making ready for another stroke. As the spring is quite Stron: considerable wei ht must be a lied t i a bit has considerable weight upon it, thus insuring fast cutting or digging.

Rotation of the drill in one direction ceases when the lower end of the housing or socket comes in contact with the shoulder 7 at the lower end of shank or rod 4.

The ball 6 becomes a stop when it reaches the lower end ofgroove 3, thus preventing the shank of the bit from being forced entirely out of the socket by the force of the spring 9.

I claim:

1. In a cable rig for'drilling Wells, of the type having a drill stem and a drill bit, means for imparting alternating rotary movement to said bit, said means including a housing having a circular bore and secured to the lower end of said stem, the wall of said bore having a semicircular spiral groove therein, a circular bit shank having a movable fit in-said bore, and having a semicircular spiral groove complementary to the groove in the bore, and a ball mounted .in the groove of the bore and connecting the housing with the bit shank.

2. In a cable rig for drilling wells, of the type having a drill stem and drill bit, means for imparting an alternating rotary move-* ment to the bit, said means comprising a housing member having a circular bore and connected with the aforesaid stem, the Wall of the bore having a semi-circular spiral groove therein, a circular drill shank having a complementary semicircular spiral groove in its circumference, a ball mounted in the groove of the bore and connecting the housing with the bit shank, an expansion spring within the bore and operating normally to force said drill shank outwardly in the bore, and coacting stop means carried by the housing and drill shank to limit the inward movement of the drill shank within the bore of the housing.

3.- In a mechanism for rotating earth drill bits, a tubular bit shank, a housing connected thereto, said housing having a spiral groove therein, and a ball mounted in said groove, the drill shank having a complementary spiral groove to receive said ball, and a yielding, cleaning finger carried by said housing and projecting into the spira groove therein.

WURLEY NIPPERT. 

